What seems like an innocent bug bite can land your toddler in the ER with a serious infection. It happened to my son, and I'm writing this so it won't happen to you.

We've got some evil mosquitoes in our backyard this summer, and both my kids have had some nasty bites. So when my son developed a big red welt on his tummy (that's it in the picture there), I didn't think much of it, even when it started looking pretty gross. We were on vacation, we were heading into the Fourth of July weekend, and it seemed to be shrinking and getting better, so I didn't worry about it.

That is, I didn't worry about it until he got up from his nap on the Fourth and not only was the bite much worse, but a rash of small, pimply bumps had spread across his stomach. My husband and I looked at each other in horror and made plans to get him to our local hospital's after-hours clinic.

He headed there with our son, my daughter and I headed off to my parents' barbecue, and we had plans to meet up after what I thought would be a quick, routine trip.

My phone rang 30 minutes later with bad news. The clinic doctor had taken one look at it and decided it was worse than what she could handle, so she sent them over to the ER. That doctor diagnosed it as MRSA (methicillin-resistant Staphylococcus aureus) infection. That's the superbug that has, in periodic outbreaks, made young, healthy people sick and sometimes even killed them. It's resistant to many antibiotics and can easily spread from person to person through skin-to-skin contact.

His infection looked like a big, painful spider bite at first, and slowly developed a pus head on it just like a nasty pimple. I honestly didn't think it was a big deal, and I was very wrong.

My daughter had scratched some bug bites a few weeks earlier, which got infected, and she was in so much pain she couldn't walk. After a round of antibiotics and some Motrin, she was fine. Our pediatrician didn't call it MRSA, but I am pretty sure that's what it was in hindsight. And given that the two of them are constantly hugging and snuggling, it makes sense that she passed it on to him.

My boy's doing well, and now just has a little welt (and a whole new set of avoidance techniques to get out of taking the very yucky medicine, none of which we're falling for). Still, I've had at least one sleepless night thinking about what could have happened had my husband not insisted on taking him in when he did. Moral of the story? A bug bite that still looks awful after a couple of days is something to worry about.